program rouse;
uses graphABC;
var
a,n,x,y:integer;
f:real;
begin
a:=2;n:=4;
f:=0;
Line(320,0,320,480);
Line(0,240,640,240);
while f<6.28 do begin
 x:=round(320 + a*Sin(n*f)*Cos(f)*40);
 y:=round(240-a*Sin(n*f)*Sin(f)*40);
 SetPixel(x,y,clred);
 f:=f+0.01;
 end;
 end.